1. Field of the Invention
The present invention is related to an improved bolt/nut structure capable of preventing from dead locking and loosening and being vibration resistive; and especially to such an improved bolt/nut structure which is manufactured to have thereon an internal threaded lining and an external threaded sleeve of one of various pitch gauges, thereby, the bolt/nut structure can have the capability of changing for coarse and fine threads, and can be used in the assembling circumstances where the screw threads collapse. This can provide the effects of preventing from dead locking and loosening and of being vibration resistive.
2. Description of the Prior Art
Conventional locking technique for bolts and nuts provides mainly on the bolts and nuts internal and external screw threads, by engaging and rotating leading between the external threads and internal threads, tight axial clamping or rotation leading action can be obtained.
However, it has been known that, among various circumstances where articles are locked by screw threads in the markets, such as in the screw coupling between the car transmission shaft and a wheel rim, the screw coupling between the airplane housings, and in the mechanical transmission members on a tunnel drilling machine with high vibrational frequency, on an oil drilling machine, a pile driver, an engine, an internal combustion engine, an air compressor and an oil compressor etc., extremely large vibration exists, so that the screw connections are subjected to loosening or breakage of screw threads.
To overcome such a trouble, however, there is only a locking technique for bolts and nuts (referring to U.S. Pat. No. 5,961,266 granted to the owner of the present invention). Wherein, the shank of a bolt is provided with a lot of axial teeth, cooperating with an external threaded sleeve in the form of a helix spring of which the wall of a hole is formed to have a lot of engaging internal teeth, in this way, the axial teeth on the shank of the bolt is engaged with the external threaded sleeve having spring nature, by the engagement of the axial teeth with the engaging internal teeth, the rotation action force in screwing tight the bolt can be transmitted, the spring nature of the external threaded sleeve can absorb the external vibration force, and can increase the engaging force between the teeth, thereby, the effects of anti-dead locking and anti-vibration can be obtained. Further, the nut is provided therein with a hole having a plurality of axial internal engaging teeth, in cooperation with an internal threaded lining in the form of a helix spring, the external wall of the internal threaded lining is made to have external engaging teeth, thereby the nut provided with the hole having a plurality of axial internal engaging teeth is engaged with the internal threaded lining having internal threads with the nature of a spring and thus can effect an engaging action between the internal engaging teeth and the external engaging teeth. In transmitting the rotational force for screwing tight the nut, the external vibration force can also be absorbed by the spring nature of the internal threaded lining, and the engaging force between the internal and external teeth can be increased; and thereby the effects of anti-dead locking, anti-vibration and loosening proofing can be obtained. However, the internal threaded lining and the external threaded sleeve are in the form of helix springs in order to match and connect with the nut and the bolt, they are required to be made to have thereon internal external engaging teeth and thus are expensive in production cost, and are not suitable for fine pitch gauges of threads, they are not good in the effect of assembling when facing to the cases of collapsing screw threads.
And the way to deal with the problem of collapsing of screw threads in the art is to enlarge the surface with collapsing of screw threads by boring, then new screw threads are tapped with a tapping tool, and a new protecting sleeve is provided on the bolt or the new tapped screw threads. In this way, an object of repairing the surface with collapsing of screw threads can be achieved, and coupling strength of the screw threads can be effectively increased. However, in practice, the process includes boring, tapping and providing protecting sleeves etc., it is inconvenient in practicing, and is not suitable for machines with vibration.
To thoroughly solve the abovementioned conventional defects of inability of getting the effects of anti-dead locking, anti-vibration and loosening proofing or of having higher production cost and being not good in the effect of assembling when facing to the cases of collapsing screw threads, and the defect of being cumbersome in practicing the new protecting sleeves as well as inferior anti-vibration and loosening-proofing, is the motive of studying and developing of the present invention.
The object of the present invention is to provide an improved anti-dead locking, anti-vibration and loosening-proof bolt/nut structure which is manufactured to have thereon an internal threaded lining or an external threaded sleeve of one of various pitch gauges, thereby, the bolt/nut structure has the capability of changing for the coarse and fine threads, and can be used in the assembling circumstances where the screw threads collapse. This can provide the effect of preventing from dead locking and loosening and of being vibration resistive, and can have the advantage of being cost low.
To get the above object, the present invention in practice has the following advantages:
The internal threaded lining and the external threaded sleeve are respectively provided for the bolt and the nut to be used as an elastic external thread and an elastic internal thread to provide the function of dead locking and loosening and of vibration resisting.
With a plurality of internal and external expansion slits on the internal and external peripheries of the helix springs with the cross section of each ring thereof in the shape of xe2x80x9c]xe2x80x9d, the springs are suitable for use on the surface with collapsing of screw threads in a simple and easy way. Moreover, the process of manufacturing includes providing a plurality of expansion slits on the internal and external peripheries of the helix springs and then the bodies are bent into the shape of the helix springs with a winding machine. Thereby, its process is simpler and easier, and its production cost is lower than that of the anti-dead locking, anti-vibration and loosening-proof bolt/nut structure stated in the technique of the U.S. Pat. No. 5,961,266.
A single or a plurality of helix springs can be provided to form the internal threaded lining or the external threaded sleeve of one of various pitch gauges, thereby, the bolt or the nut structure has the capability of changing for the coarse and fine threads.
With the above statement, the improved anti-dead locking, anti-vibration and loosening-proof bolt/nut structure of the present invention can be used for rotating locking with a conventional nut or bolt, or can be used in a combined way. It is sure that, when in assembling in a closed type hole with screw threads without using a nut structure, the bolt structure of the present invention can be singly used for assembling in the closed type hole with screw threads to get the effects of anti-dead locking, anti-vibration and loosening-proofing, and is suitable for using in the assembling circumstances where the screw threads collapse as well.
The present invention will be apparent after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.